Abstract: The disclosure relates to a product moisture control system for use in a product steam dryer of the type which removes moisture from wet product material, wherein the wet product material is contacted with steam tubes for heating the material and evaporating the moisture therein. The control system includes a first control loop which senses the moisture content of the dried material and establishes at predetermined times corrections to the steam pressure within the steam tubes to provide processed material having a desired moisture content. The system also includes a second control loop which continuously detects the steam pressure and maintains the steam pressure substantially constant during the time intervals between the predetermined steam pressure correction times.